Compasses.



R. W. GRAHAM.

. OOMPASSES. I APPLICATION FILED JUNE 13, 1908. RENEWED D110. 14; 1910.

988, 1 88. Patented Mar. 28, 1911.

Inventor UNTTE %TATE% PATENT @FFTQE.

RICHARD WILLIAM GRAHAM, 0F WINNIPEG, MANITOBA, CANADA.

COMPASSES.

Application filed. June 13, 1908, Serial No. 438,374.

To all whom it may concern:

Be it known that I, RICHARD VILLIAM GRAHAM, of the city of Winnipeg, inthe Province of Manitoba, Canada, contractor, have invented certain newand useful In1- provements in Compasses, of which the following is thespecification.

My invention relates to compasses, and the object of the invention is todevise a compass which will outline a circle on an irregular surface andwhich further will draw the projection of a circle on a plane orinclined surface, and it consists essentially in a standard; anadjustable shank sleeved and slidable on the standard, and a quadrantsupporting the standard and adjustably interconnected with it, the partsbeing arranged and constructed as hereinafter more particularlydescribed.

Figure 1 is a side elevation of my complete compass. Fig. 2 is a reverseview of the shank detached, as in Fig. 1. Fig. 3 is detailed view of thelower portion of the standard and the quadrant showing them in aposition at right angles to that shown in Fig. 1. Fig. 4 is a plan viewof a portion of the quadrant and its base. Fig. 5 is an'inverted planview of the quadrant and the receiver.

In the drawings like characters of reference indicate correspondingparts in each figure.

I have found considerable difficulty in instances where it has beennecessary for me to cut an opening in such places as the inclined roofof a building to allow for the insertion of a pipe. In order to saveconsiderable time and to prevent waste of material I have conceived thecompass as now described and although I have mentioned particularly aninclined roof, the compass can be used to great advantage in many otherinstances which will be apparent when I have described it further.

1 represents a quadrant which is supported by a base 2, the base beingat right angles to the quadrant, and having foot pieces 3 supporting itat its corners. The quadrant is marked as is usual, in degrees andminutes, and the base is supplied with an elongated central opening 4,the purpose of which will shortly be explained.

5 is a circular metallic shank provided at the top with a knob 6 and hasits lower end passing into a receiver as later described.

Specification of Letters Patent.

Patented Mar. 28, 12111.

Renewed December 14, 1910. Serial No. 597,360.

The knob is screwed onto the shank as shown in Fig. 1.

7 is a conical receiver having its point passing into and through aplate 8, the plate being pivotally supported by a pair of op posing setscrews 9 and 10. The screws are provided with conical points which passinto correspondingly shaped recesses provided in the plate. The lowerend of the standard is firmly secured within the-opening in the receiver7.

11 is a slot cut in the quadrant concentric to the screws 9 and 10, and12 is a thumb screw passing through the slot and screwing into thestandard, thereby holding the standard in whatever may be its adjustedposition.

13 is an index pointer fastened or secured to the standard adjacent thequadrant and with its end playing over and registering the degrees onthe quadrant.

14 is a sleeve slidably supported on the standard and adjustably held inposition by a thumb screw 15 which engages with the standard.

16 is a knob supplied on the sleeve in order to make the compass morereadily handled when using.

17 is a shank having its lower end pointed at 18 and its upper endenlarged at 19 and provided with lugs 20 and 21 whereby the shank ispivotally fastened to a lug 22 projecting from the sleeve, by a screw23.

24 is a bar passing outwardly from the sleeve to which it is firmlysecured and bent upwardly concentric with the screw 23. The enlargedportion of the shank is provided with an opening 25 into which is passedthe bar 24-.

26 is an adjusting screw carried by the shank and screwing into theopening and against the bar 24.

27 is a pencil fastened to the shank by a band 28 and secured inposition by a flat spring 29 fastened to the interior wall of the band,the spring being adapted to press continuously against the pencil.

In order to understand my invention completely T will now give a shortdescription of the manner in which the compass is used. When it isrequired to draw the projection of a circle in the horizontal plane onan inclined plane such as a roof, the standard is held vertically, or atright angles to the plane of the circle. The shank is set by the screw25 so that the distance from the pen ia-n.

oil point-to the tip or apex of the receiver 7 is equal to the radius ofthe circle. The shank is then turned by the knob 16 and the standard iskept stationary in the vertical position. As the shank is secured to thesleeve which is slidable on the standard itv can accommodate itself tothe condition caused by the inclination of the roof. When the shank hasbeen turned completely around, the projected circle will be outlined bythe pencil point on the inclined surface. The compass can With equaladvantage be used Where one. is. drawing plans and requires a projectionof a similar circle such as that already mentioned. In the above casethe shankof the compass is kept in the vertical position and the. roofis. inclined, but in the latter case the plan on Which the drawing isbeing madeis. in the horizontal plane and the standard is inclinedtofWhatever-the angle of the roof may be. The pencil point is set asbefore at the proper distance from the apex of the receiver'- and thequadrant rests on the horizontal surface. The standard is adjusted tothe angle of the roof by means of the screw 12;, and When holding it inthis position the shank; is turned on the standard. The pencil pointWill outline on they horizontal surface the same projection as isoutlined on the inclined surface. If it be desired to use the compass tooutline a circle the standard with the receiver is removed from thequadrant by loosening the screW 12 and raising the point of the receiverfrom the opening in the plate 8.

What I claim as my invention is A compass comprising a standard having apointed end, a plate 8 having a hole therein into which the pointed endof the standard passes, a base having a slot therein, screws passingthrough the base and pivotally sup porting the plate 8 in theslottherein, a

quadrant secured to the base and having a slot therein concentric to thescrews and hav ing graduations thereon, a thumbscreiv pass- 1 RICHARDWILLIAM GRAHAM.

In the presence, of-

JAs. M. TAILEY, GERAL S. RoXB RcI-I.

Copies. of; this patent may;v be. obtained for five cents each, by,addressing the Commissioner of Iatents, Washington, D C.

